AV communication control circuit for realizing copyright protection with respect to radio LAN

ABSTRACT

An AV communication control circuit suitable for a radio LAN-LSI in a radio AV transmission/reception device is formed by a copyright protection processing unit configured to carry out a copyright protection processing with respect to AV data entered from an AV stream signal line, a selection unit configured to select either one of AV data entered from an AV stream signal line through the copyright protection processing unit and AV data entered from a general purpose bus, and a transmission control unit configured to carry out control for transmitting AV data selected by the selection unit to a network.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.11/979,228 filed Oct. 31, 2007, and is based upon and claims the benefitof priority from U.S. patent application Ser. No. 10/722,468, filed Nov.28, 2003, which claims the benefit from Japanese Patent Application No.2002-348732, filed Nov. 29, 2002, the entire contents of all of whichare incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an AV communication control circuit andan AV communication control program for transmitting or receiving AVdata while realizing the copyright protection.

2. Description of the Related Art

The products called digital information home electronics are becomingpopular. These products are expected to become even more popular inconjunction with the start of the digital broadcasting, and include allkinds of products for handling digital data and digital contents such asdigital broadcasting compatible TV, set-top box, digital VTR, DVDplayer, hard disk recorder, etc.

The quality of the digital data and digital contents will not bedegraded even when they are copied, and the copies can be made easily,so that there is a need to provide a measure for the copyrightprotection in advance. For example, in the IEEE 1394 which is a digitalnetwork for connecting digital AV devices, the authentication and keyexchange mechanism and the data encryption function are provided.

Here, consider a case of transferring the AV data that requires thecopyright protection, from some transmission device. What needs to betaken into consideration here is that the copyright protectionpresupposes to allow the exchange of the AV data within a range ofpersonal (or family) entertainment, but to prevent the exchange of theAV data with a third person (unless the permission from the copyrightholder is given).

Usually, the exchange of data with a third person is carried out througha public network such as the Internet, and the exchange of data insidethe home or the personal exchange of data is carried out on a closedhome network such as the IEEE 1394 or a radio network.

The IEEE 1394 is a representative digital network for connecting digitalAV devices, and provided with the authentication and key exchangemechanism and the data encryption function. This mechanism is calledDTCP (Digital Transmission Control Protection) (see documents disclosedat “http://www.dtla.com”, for example). Basically, the DTCP encryptionand the authentication and key exchange mechanism are provided inside anLSI of the IEEE 1394, and it is often provided with a mechanism forencrypting the AV data immediately before transmitting them to the IEEE1394, and decrypting them immediately after receiving them, in the caseof transmitting/receiving AV data to be protected through the IEEE 1394(see Japanese Patent Application Laid Open No. 2001-308775).

What is likely to attract attentions in near future is the home radioLAN. The IEEE 802.11 standard which is one of the radio LAN standards israpidly spreading to offices/homes, and it is highly likely to carry outthe exchange of the AV data that require the protection on the radio LANin near future.

Even in this type of the radio LAN, there is a need to consider thecopyright protection mechanism, and such a mechanism will most likely beincorporated in an LSI of the radio LAN, in view of the past experienceof the IEEE 1394.

However, the known radio LAN has been basically targeting a PC network.The radio LAN interface in the PC (interface between a CPU of the PC andthe radio LAN) is provided through a general purpose bus such as PCIbus, and for this reason, the integrated circuit of the radio LAN oftenhas a PCI bus interface.

On the other hand, in near future, it is highly likely that the radioLAN is implemented on the so called AV devices such as TV, DVD, etc. Aninterface between an AV processing unit (such as AV decoder) and anetwork in these AV devices is in general an interface for directlyexchanging AV stream data, for various reasons such as securing thesynchronization. Thus the integrated circuit of the radio LAN shouldpreferably have this AV stream interface, Also, the implementation ofthe copyright protection function is indispensable.

However, when the copyright protection function is provided inside theintegrated circuit of the radio LAN, the AV data to beinputted/outputted to/from the integrated circuit of the radio LAN haveto be non-encrypted raw data, and this implies that the raw data willflow through the general purpose bus such as PCI bus. In the general PC,it is relatively easy to produce a program for storing data on thegeneral purpose bus into a specific region, so that the allowing the rawAV data to flow through the general purpose bus is problematic.

BRIEF SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide an AVcommunication control circuit and an AV communication control programcapable of efficiently carrying out AV data processing and copyrightprotection processing according to a type of a device on which it isimplemented and an interface specification.

According to one aspect of the present invention there is provided an AVcommunication control circuit, comprising: a copyright protectionprocessing unit configured to carry out a copyright protectionprocessing with respect to AV data entered from an AV stream signalline; a selection unit configured to select either one of AV dataentered from an AV stream signal line and AV data entered from a generalpurpose bus; and a transmission control unit configured to carry outcontrol for transmitting AV data selected by the selection unit to anetwork.

According to another aspect of the present invention there is providedan AV communication control circuit, comprising: a reception controlunit configured to carry out control for receiving AV data through anetwork; a selection unit configured to select a target to supplyreceived AV data as either one of an AV stream internal signal line anda general purpose internal bus; and a copyright protection processingunit configured to carry out a copyright protection processing withrespect to AV data supplied to the AV stream internal signal line whenthe selection unit selects the AV stream internal signal line.

According to another aspect of the present invention there is provided acomputer program product for causing a computer to function as an AVcommunication control circuit, the computer program product comprising:a first computer program code for causing the computer to carry out acopyright protection processing with respect to AV data entered from anAV stream signal line; a second computer program code for causing thecomputer to select either one of AV data entered from an AV streamsignal line and AV data entered from a general purpose bus; and a thirdcomputer program code for causing the computer to carry out control fortransmitting AV data selected by the selection unit to a network.

According to another aspect of the present invention there is provided acomputer program product for causing a computer to function as an AVcommunication control circuit, the computer program product comprising:a first computer program code for causing the computer to carry outcontrol for receiving AV data through a network; a second computerprogram code for causing the computer to select a target to supplyreceived AV data as either one of an AV stream internal signal line anda general purpose internal bus; and a third computer program code forcausing the computer to carry out a copyright protection processing withrespect to AV data supplied to the AV stream internal signal line whenthe selection unit selects the AV stream internal signal line.

Other features and advantages of the present invention will becomeapparent from the following description taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing an overall configuration of an AVcommunication system according to one embodiment of the presentinvention.

FIG. 2 is a block diagram showing one exemplary internal configurationof a radio AV transmission device in the AV communication system of FIG.1.

FIG. 3 is a block diagram showing another exemplary internalconfiguration of a radio AV transmission device in the AV communicationsystem of FIG. 1.

FIG. 4 is a block diagram showing an exemplary internal configuration ofa radio LAN-LSI that can be utilized in either one of the radio AVtransmission device configurations of FIG. 2 and FIG. 3.

FIG. 5 is a block diagram showing an exemplary internal configuration ofa radio LAN-LSI with a single AV data input terminal that can beutilized in either one of the radio AV transmission deviceconfigurations of FIG. 2 and FIG. 3.

FIG. 6 is a block diagram showing one exemplary internal configurationof a radio AV reception device in the AV communication system of FIG. 1.

FIG. 7 is a block diagram showing another exemplary internalconfiguration of a radio AV reception device in the AV communicationsystem of FIG. 1.

FIG. 8 is a block diagram showing an exemplary internal configuration ofa radio LAN-LSI that can be utilized in either one of the radio AVreception device configurations of FIG. 6 and FIG. 7.

FIG. 9 is a block diagram showing an exemplary internal configuration ofa radio LAN-LSI with a single external connection terminal that can beutilized in either one of the radio AV reception device configurationsof FIG. 6 and FIG. 7.

FIG. 10 is a sequence chart showing an AV data transmission/receptionsequence in the AV communication system of FIG. 1.

FIG. 11 is a block diagram showing an exemplary internal configurationof a radio LAN-LSI with a general purpose bus encryption processing unitthat can be utilized in either one of the radio AV transmission deviceconfigurations of FIG. 2 and FIG. 3.

FIG. 12 is a block diagram showing an exemplary internal configurationof a radio LAN-LSI with a general purpose bus encryption processing unitthat can be utilized in either one of the radio AV reception deviceconfigurations of FIG. 6 and FIG. 7.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIG. 1 to FIG. 12, embodiments of the AV communicationcontrol circuit and the AV communication control program according tothe present invention will be described in detail.

FIG. 1 shows an overall configuration of an AV communication systemaccording to one embodiment of the present invention. The AVcommunication system of FIG. 1 has a radio AV transmission device 1 fortransmitting AV data by radio, and a radio AV reception device 3 forreceiving the AV data from the radio AV transmission device 1 through aradio network 2.

The radio network 2 of FIG. 1 is assumed to be a network inside thehome, but it is not necessarily a radio network, and can be a wirednetwork such as the Ethernet or a mixed network in which a radio networkand a wired network are connected by bridge. Here, the radio network 2is a radio LAN such as that of the IEEE 802.11a or the IEEE 802.11b, forexample.

The radio AV transmission device 1 is a device capable of becoming asource device of the AV data such as TV, set-top box, DVD player, etc.The general TV or set-top box does not have a large data buffer betweenan MPEG processing unit and a radio LAN-LSI, but has an interface fordirectly exchanging AV streams and synchronization clocks instead.

On the other hand, the radio AV reception device 3 is a device capableof a sink device of the AV data such as a display device, speaker oraudio/video recording device of the TV or the like.

FIG. 2 shows an exemplary internal configuration of the radio AVtransmission device 1 of FIG. 1. This configuration is intended to beused mainly in a dedicated AV device such as DVD player. The radio AVtransmission device 1 of FIG. 2 has a radio LAN-LSI 4 and an MPEGprocessing unit 5. For example, the MPEG processing unit 5 is formed byan MPEG encoder with a function for MPEG encoding video signals, an MPEGreception unit with a function for receiving video signals (of the TVbroadcast, for example), and an MPEG storage unit with a function forstoring video signals (such as hard disk or DVD, for example). Also, theMPEG processing unit 5 has a function for transmitting the digital AVdata that require the copyright protection, to the radio LAN-LSI 4.

In the MPEG processing unit 5, at least one terminal for outputting MPEGdata and clock is provided, and the radio LAN-LSI 4 is connected to thisterminal.

The radio LAN-LSI 4 has a function for carrying out radio LANtransmission/reception control, as well as a function for carrying outthe copyright protection processing and the AV data format processing.

FIG. 3 shows another exemplary internal configuration of the radio AVtransmission device 1 of FIG. 1. This configuration is intended to beused mainly in a PC. The radio AV transmission device 1 of FIG. 3 has aCPU 7, a memory 8 and a radio LAN-LSI 4, which are connected to ageneral purpose bus 6 such as PCI bus.

The CPU 7 executes the MPEG processing by software. Note that it is alsopossible to provide a functional block for executing the MPEG processingby hardware inside the CPU 7.

The processing power of the CPU 7 has been significantly increased overrecent years, so that a configuration for carrying out the MPEGprocessing by software as shown in FIG. 3 is expected to becomewidespread rapidly.

To develop configurations of the radio LAN-LSI 4 compatible with theradio AV transmission device configurations of FIG. 2 and FIG. 3separately is wasteful in terms of cost, so that it is preferable tohave an identical radio LAN-LSI 4 utilizable in either one of the radioAV transmission device configurations of FIG. 2 and FIG. 3.

FIG. 4 shows an exemplary internal configuration of the radio LAN-LSI 4which is utilizable in either one of the radio AV transmission deviceconfigurations of FIG. 2 and FIG. 3. The radio LAN-LSI 4 of FIG. 4 has aclock transmission unit 11, a DTCP processing unit 12, a general purposebus interface 13, a buffer 14, a selector 15, an interface selectionunit 16, and a radio LAN processing unit 17.

The clock transmission unit 11 outputs the synchronization clock for theAV data entered from an external, to the radio LAN side through theradio LAN processing unit 17. The DTCP processing unit 12 carries outthe DTCP copyright protection processing with respect to the AV datasupplied from the MPEG processing unit 5 of FIG. 2 through an AV streamsignal line, The buffer 14 temporarily stores the AV data supplied fromthe CPU 7 of FIG. 3 through the general purpose bus 6 and the generalpurpose bus interface 13.

The selector 15 selects either one of the AV data for which thecopyright protection processing is carried out by the DTCP processingunit 12 and the AV data supplied from the general purpose bus withoutcarrying out the copyright protection processing. The selection at theselector 15 is made by the interface selection unit 16. The AV dataselected at the selector 15 are modulated at the radio LAN processingunit 17 and then transmitted to the radio network 2.

The reason for carrying out the copyright protection processing at theDTCP processing unit 12 with respect to the AV data supplied through theAV stream signal line is that, in the case of the radio AV transmissiondevice configuration of FIG. 2, the AV stream signal line between theMPEG processing unit 5 and the radio LAN-LSI 4 is not connected withanywhere else so that there is no need to carry out the copyrightprotection processing with respect to the AV data on this AV streamsignal line, and therefore the copyright protection processing iscarried out after the AV data are entered into the radio LAN-LSI 4.

On the other hand, in the case of the radio AV transmission deviceconfiguration of FIG. 3, the AV data are exchanged through the generalpurpose bus 6 so that if the copyright protection processing is to becarried out inside the radio LAN-LSI 4, non-encrypted raw AV data wouldflow through the general purpose bus 6 and there is a possibility ofhaving the AV data illegally acquired by an AV capture device or thelike that is connected to the general purpose bus 6. For this reason, inthe case of the radio AV transmission device configuration of FIG. 3,the copyright protection processing is carried out by software at theCPU 7 side, and the encrypted AV data are supplied to the generalpurpose bus 6. Consequently, there is no need to carry out the copyrightprotection processing inside the radio LAN-LSI 4.

The radio LAN-LSI 4 of FIG. 4 has an external connection terminal t1 tobe connected to the AV stream signal line, and an external connectionterminal t2 to be connected to the general purpose bus. The radioLAN-LSI 4 in practice has many other terminals as well, so that it ispreferable to reduce the number of terminals as much as possible.

For this reason, FIG. 5 shows an exemplary internal configuration of theradio LAN-LSI 4 which has a single AV data input terminal. In FIG. 5,the constituent elements identical to those of FIG. 4 are given the samereference numerals, and the difference will be mainly described in thefollowing.

The radio LAN-LSI 4 of FIG. 5 has a single external connection terminalt3 which is capable of being connected to either one of the AV streamsignal line and the general purpose bus, and a selector 18 connected tothis external connection terminal t3. This selector 18 selects a targetfor supplying the AV data entered at the external connection terminal t3as either an AV stream internal signal line or a general purposeinternal bus, and the selection is made by the interface selection unit16, similarly as in the case of the selector 15. The interface selectionunit 16 makes the selections at the selectors 15 and 18 insynchronization with each other.

FIG. 6 shows an exemplary internal configuration of the radio AVreception device 3 of FIG. 1. This configuration is intended to be usedmainly in a dedicated AV device such as TV. The radio AV receptiondevice 3 of FIG. 6 has a radio LAN-LSI 21, an MPEG decoder 22 fordecoding the received AV data in the MPEG format, and a display controlunit 24 for carrying out control to display the received AV data on adisplay unit 23.

The radio LAN-LSI 21 carries out the radio LAN transmission/receptioncontrol, the copyright protection processing, and the AV data formatprocessing.

FIG. 7 shows another exemplary internal configuration of the radio AVreception device 3 of FIG. 1. This configuration is intended to be usedmainly in a PC. The radio AV reception device 3 of FIG. 7 has a CPU 26,a memory 27, a display memory and display unit 28, and a radio LAN-LSI21, which are connected to a general purpose bus 25 such as PCI bus.

The CPU 26 executes the decoding processing of the AV data in the MPEGformat and the processing for storing into the memory 27 by software.

FIG. 8 shows an exemplary internal configuration of the radio LAN-LSI 21which is utilizable in either one of the radio AV reception deviceconfigurations of FIG. 6 and FIG. 7. The radio LAN-LSI 21 of FIG. 8 hasa radio LAN processing unit 31, a clock extraction unit 32, a selector33, an interface selection unit 34, a DTCP processing unit 35, a buffer36, and a general purpose bus interface 37.

The radio LAN processing unit 31 receives radio signals containing theAV data through the radio network 2. The clock extraction unit 32extracts clock synchronized with the AV data from the received radiosignals or the received AV data.

The selector 33 selects a target for supplying the AV data contained inthe received radio signals as either an AV stream signal line or ageneral purpose bus. The AV data for the AV stream signal line selectedby the selector 33 are decrypted at the DTCP processing unit 35, andsupplied to the AV stream signal line. On the other hand, the AV datafor the general purpose bus selected by the selector 33 are temporarilystored in the buffer 36 and then supplied to the general purpose busthrough the general purpose bus interface 37.

The AV data supplied to the AV stream signal line from the radio LAN-LSI21 of FIG. 8 are entered into the MPEG decoder 22 of FIG. 6 and decodedthere. Also, the AV data supplied to the general purpose bus from theradio LAN-LSI 21 of FIG. 8 are entered into the CPU 26 of FIG. 7 anddecoded there by software.

The radio LAN-LSI 21 of FIG. 8 has an external connection terminal t4 tobe connected to the AV stream signal line, and an external connectionterminal t5 to be connected to the general purpose bus. FIG. 9 shows anexemplary internal configuration of the radio LAN-LSI 21 which has asingle external connection terminal. In FIG. 9, the constituent elementsidentical to those of FIG. 8 are given the same reference numerals, andthe difference will be mainly described in the following.

The radio LAN-LSI 21 of FIG. 9 has a single external connection terminalt6 which is capable of being connected to either one of the AV streamsignal line and the general purpose bus, and a selector 38 connected tothis external connection terminal t6. This selector 38 selects eitherone of the AV data outputted from the DTCP processing unit 35 and the AVdata outputted from the general purpose bus interface unit 37, andsupplies the selected AV data to the external connection terminal t6.The selection is made by the interface selection unit 34, similarly asin the case of the selector 33. The interface selection unit 34 makesthe selections at the selectors 33 and 38 in synchronization with eachother.

FIG. 10 shows a AV data transmission/reception sequence in the AVcommunication system of FIG. 1. First, the AV control command forrequesting a playback of the AV data is transmitted, by TCP/IP or UDP/IPfor example, from the radio AV reception device 3 to the radio AVtransmission device 1 (step Si).

Upon receiving this request, the radio AV transmission device 1 encryptsthe AV data (step S2). Next, the radio AV transmission device 1transmits the AV data, by RTP/IP for example, to the radio AV receptiondevice 3 (step S3). At this point, in the case of the AV data thatrequire the copyright protection, the DTCP encryption is carried out andthe AV data are transmitted with the transmission port number=#x, thereception port number=#y, and TTL (Time To Live)=1.

The radio AV reception device 3 that received the encrypted AV datarecognizes that they are encrypted when the AV data are received. Then,the radio AV reception device 3 assigns specific IP address and portnumber (or the number that can identify an RTP connection such as SSRC)and requests the authentication and key exchange for that RTPconnection.

When the radio AV transmission device 1 responds to this request, theauthentication and key exchange procedure is carried out by using theradio layer packet or the Ethernet frame, between the radio AVtransmission device 1 and the radio AV reception device 3 (step S5). Asa result, the radio AV reception device 3 acquires a decryption key(step S6), and decrypts the AV data by using this decryption key.

In this way, in this embodiment, the radio LAN-LSI 4 which carries outthe radio transmission of the AV data supplied through the AV streamafter carrying out the copyright protection processing, and carries outthe radio transmission of the AV data supplied through the generalpurpose bus without any change is provided inside the radio AVtransmission device 1, so that the identical radio LAN-LSI 4 can beutilized in either one of the radio AV transmission device 1 having theAV stream signal line and the radio AV transmission device 1 having thegeneral purpose bus, and there is no need to develop the compatible LSIsseparately for them so that the LSI development cost can be reduced.

Also, in this embodiment, the radio LAN-LSI 21 which transmits the AVdata after carrying out the copyright protection processing in the caseof transmitting the AV data contained in the received radio signals tothe AV stream signal line, and transmits the AV data without carryingout the copyright protection processing in the case of transmitting theAV data to the general purpose bus is provided inside the radio AVreception device 3, so that the identical radio LAN-LSI 21 can beutilized in either one of the radio AV reception device having the AVstream signal line and the radio AV reception device 3 having thegeneral purpose bus, and there is no need to develop the compatible LSIsseparately for them so that the LSI development cost can be reduced.

In the above described embodiment, the exemplary case where the AV datasupplied through the general purpose bus are entered into the radioLAN-LSI 4 in an encrypted state, but it is also possible to carry outthe DTCP encryption processing with respect to the AV data on thegeneral purpose bus inside the radio LAN-LSI 4, separately from theencryption on the general purpose bus. The internal configurations ofthe radio LAN-LSIs 4 and 21 in this case are as shown in FIG. 11 andFIG. 12, respectively. A general purpose bus encryption processing unit19 or 39 in FIG. 11 or FIG. 12 carries out the copyright protectionprocessing with respect to the AV data on the general purpose bus. Atthis point, the authentication and key exchange will be carried out inadvance with the correspondent (the MPEG software on the CPU in thisembodiment) for exchanging the AV data through the general purpose bus.

The radio LAN-LSI 4 or 21 described in the above embodiments may berealized in a form of software. In that case, a program for realizingfunctions of the radio LAN-LSI 4 or 21 is stored in a recording mediumsuch as floppy disk or CD-ROM, which can be read out from there andexecuted by a computer. The recording medium is not necessarily limitedto a portable one such as a magnetic disk or an optical disk, and can bea fixed one such as a hard disk device or a memory device.

It is also possible to distribute a program for realizing functions ofthe radio LAN-LSI 4 or 21 through communication channels (includingthose of the radio communications) of the Internet or the like. Inaddition, this program may be distributed in an encrypted, modulated orcompressed state, through the wired channels of the Internet or the likeor the radio channels, or this program may be distributed by storing itin a recording medium.

As described above, according to the present invention, it is madepossible to transmit/receive either one of the AV data on the AV streamsignal line and the AV data on the general purpose bus, so that there isno need to prepare dedicated integrated circuits for these two cases,and it is possible to reduce the designing and manufacturing cost of theintegrated circuit.

It is also to be noted that, besides those already mentioned above, manymodifications and variations of the above embodiments may be madewithout departing from the novel and advantageous features of thepresent invention. Accordingly, all such modifications and variationsare intended to be included within the scope of the appended claims.

1. An AV communication control circuit, comprising: a copyrightprotection processing unit configured to carry out a copyrightprotection processing for encrypting AV data entered from an AV streamsignal line; an interface selection unit configured to make a selectionof AV data to be transmitted to a network; a selection unit configuredto select either one of AV data entered from an AV stream signal linethrough the copyright protection processing unit and AV data enteredfrom a general purpose bus, based on the selection by the interfaceselection unit; a transmission control unit configured to carry outcontrol for transmitting AV data selected by the selection unit to thenetwork; a first external connection terminal to receive AV data fromthe AV stream signal line and to supply received AV data to thecopyright protection processing unit, a second external connectionterminal to receive AV data from the general purpose bus and to supplyreceived AV data to the selection unit; wherein the copyright protectionprocessing unit carries out the copyright protection processing withrespect to AV data which is supplied by the first external connectionterminal, for which the copyright protection processing has not beencarried out before entering the AV communication control circuit, andthe selection unit selects either one of (1) AV data which is enteredfrom the AV stream signal line via the first external connectionterminal and the copyright protection unit, for which the copyrightprotection processing is carried out by the copyright protection unit,and (2) AV data which is entered from the general purpose bus via thesecond external connection terminal, for which the copyright protectionprocessing has been carried out before entering the AV communicationcontrol circuit.
 2. A non-transitory computer readable medium includingcomputer executable instructions, which when executed by a computer,cause the computer to function as an AV communication control circuitthat performs a method comprising: carrying out a copyright protectionprocessing for encrypting AV data entered from an AV stream signal linefor which the copyright protection processing has not been carried outbefore entering the AV communication control circuit; making a selectionof AV data to be transmitted to a network; selecting either one of (1)AV data entered from an AV stream signal line for which the copyrightprotection processing is carried out by the carrying out and (2) AV dataentered from a general purpose bus for which the copyright protectionprocessing has been carried out before entering the AV communicationcontrol circuit, based on the selection by the making a selection; andcarrying out control for transmitting AV data selected by the selectingto the network.